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1.
2.
Alejandro Colina Betzabé Sulbarán-de-Ferrer Cateryna Aiello Alexis Ferrer 《Applied biochemistry and biotechnology》2003,108(1-3):715-724
Xylanase production of Trichoderma reesei Rut C-30 was examined at different initial pH values (4.8, 5.9, and 7.0) on rice straw in shake flasks, and in a fermentor,
for the best pH condition. Enzyme performance was tested on ammonia-treated dwarf elephant grass. The maximum xylanase activities,
92 and 122 IU/mL, were obtained at pH 4.8 in the shake flasks and fermentor, respectively, in which good growth of the fungus
was observed during the first 24 h and consumption of proteins dissolved from the rice straw caused the pH to rise later to
values between 6.4 and 6.7 (optimal for xylanase production). The xylanases from T. reesei were as effective as Multifect XL, a commercial enzyme preparation, in hydrolyzing ammonia-treated elephant grass. 相似文献
3.
Magnetic domains in a two-dimensional ferromagnetic metal and the existence of gapless magnons confined along the domain walls are studied starting from the XXZ model for localized spins. The relevance for transport properties of the inelastic interaction between conduction electrons and the localized magnons is analysed, and conductivity calculations presented. 相似文献
4.
A. Prats Ferrer B. Eynard P. Di Francesco J.-B. Zuber 《Journal of statistical physics》2007,129(5-6):885-935
The Harish-Chandra correlation functions, i.e. integrals over compact groups of invariant monomials
with the weight exp tr (X
Ω
Y
Ω
†
) are computed for the orthogonal and symplectic groups. We proceed in two steps. First, the integral over the compact group
is recast into a Gaussian integral over strictly upper triangular complex matrices (with some additional symmetries), supplemented
by a summation over the Weyl group. This result follows from the study of loop equations in an associated two-matrix integral
and may be viewed as the adequate version of Duistermaat–Heckman’s theorem for our correlation function integrals. Secondly,
the Gaussian integration over triangular matrices is carried out and leads to compact determinantal expressions. 相似文献
5.
Salvador Ferrer Odile Robach Olivier Balmes Helena Isern Iona Popa Marcelo Ackerman 《Surface science》2010,604(21-22):1840-1844
Fe(001) surfaces of whiskers of good crystalline quality were oxidized in a pressure range from 10? 7 mbar to 1 bar at different temperatures. Epitaxial Fe3O4 and FeO thin films with negligible strain were grown depending on the oxidation temperatures. The kinetics of the oxide thickness growth was measured and compared with the predictions of the Fromhold–Cook theory for oxidation of metals. Some discrepancies were found and a possible explanation is presented. 相似文献
6.
A photoemission study, using a synchrotron source, on the deposition of submonolayer amounts of Au on Pt(111) has been performed. The Au 4f emission shifts continuously to higher binding energies for increasing Au coverages. A good fit to the experimental spectra has been obtained by only one Doniac-Sunjic function. We discuss the initial versus final state effects in photoemission experiments on small supported particles. 相似文献
7.
8.
About one monolayer of Ti3+ species is detectable at the surface of reduced SrTiO3(111) single crystals by XPS and UPS. O2, H2 and H2O have been adsorbed in the dark and the decrease on the concentration of the Ti3+ species has been monitored as a function of the gas exposures. Subsequent band gap illumination partially restores the Ti3+ initial concentration in the cases of O2 and H2 exposures but not in the case of H2O. The Ti3+ photogeneration on the oxygen covered surface is associated with oxygen photodesorption as indicated by XPS and UPS. UPS measurements give evidence for surface hydroxylation resulting from water and hydrogen adsorption. The activity of the stoichiometric SrTiO3(111) crystal face for O2 and H2 adsorption is very low when compared with the reduced SrTiO3 samples. 相似文献
9.
IfA is a -algebra on setX, thenl
0
(X,A) is a barrelled space of class 0. IfA is an algebra, there are conditions which imply thatl
0
(X,A) is suprabarelled. Here, wheneverA is an algebra, we give conditions forl
0
(X,A) to be not barrelled which are related with the existence of non-trivial convergent sequences.Supported in part by DGICYT, project PB91-0407 and by the Institució Valenciana d'Estudis i Investigació, project 023. 相似文献
10.
On the basis of a plane-wave spectrum representation, the polarization features of a transverse quasimonochromatic non-paraxial field have been studied. A relationship has been established between the polarization characteristics in the near field and the coherence and symmetry properties of the beam in the far field. 相似文献